Electric iron



Feb. 13, 1951 C, H, SPARKLIN 2,541,119

ELECTRIC IRON Original Filed May 4, 1945 3 Sheets-Sheet l Feb. 13, 1951c. H. SPARKLIN ELECTRIC IRON 3 Sheets-Sheet 2 Original Filed May 4, 1945Feb. 13, 1951 c. H. sPARKLlN ELECTRIC IRON l5 Sheets-Sheet 3 OriginalFiled May 4, 1945 Patented Feb. 13, 1951 ELECTRIC IRON Charles H.Sparklin, Chicago, Ill., assignor to Birtman Electric Company, -acorporation of Illinois Original application May 9, 1945, Serial No.591,911. Divided and this application October 3, 1946, Serial No.700,957

5 Claims. 1

This -invention relates toa heat regulating iron and more particularlyto a sadiron in which .heat indicating means are provided for indicatingthe setting of the thermostat at a point .remote from the means ofadjusting the same.

In my copending application, Serial No. 535,645, led May l5, 1944, nowyPatent #2,457,185 `issued Dec, 28.J 1948 a thermostatic adjustment ispositioned in a part of the .iron convenient to the fingers with theindicia placed with Van indicator in a position on the iron convenientyto the eye. This application also includes superimposi'ton of thesetting indicator and the temperature indicator so that the operator.may ascertain at a single glance how `the actual temperature of theiron corresponds to the pre-determined setting.

In the .present invention .I have perfected a new iron having athermostatic control member which does not require movement through anon-operating temperature range of the iron. When the off position isreached, the contact points of a switch are forcibly separated andmaintained separated. This enables almost the entire range of thethermostatic adjustment to be used for adjusting the iron within theoperating range. The abrupt change is preferably accomplished by havingthe control move from off position to high position and thence to low,but the on position may be at the low end, although this is lessdesirable.

'I'he invention will be described in considerable detail as related tothe embodiment of the same set out in the accompanying drawings. -Of thedrawings, Fig. 1 isa side elevation of an iron embodying the feature ofthis invention; Fig. 2 isa plan view of the iron of Fig. 1; Fig. 3 is aside elevation, partially in section; Fig. 4 is a section taken alongline II-4 of Fig. 3; Fig. 5 is a section taken along line 5 5 of Fig. 3;Fig. I6 is a .section taken along -line 6--6 vof Fig. 3; and Fig. 7 is asection taken along line I-l of Fig. 3.

As shown in the drawings, the iron I 0 comprises a sole plate II and a'hood l2 which together dene the body portion of the iron, a handleysupport I3, a handle I4 containing openings 48 in either side at therear for positioning an electric cord, and a control knob I5. The usualform of snap vacting thermostat I-6 is provided in the body y Thissecond himetal element is fastened to another section of spring steel2l. The second birnetal element 25 provides sharper control for theswitch for when it is heated it curls downward in opposite direction tothat of the rst bimetal element i5. rihis construction results in athermostatic switch in which very sharp control is provided.

The thermostatic switch is controlled by rotation of the control knob i5in the following manner. The knob I5 has a central opening in which aninternal sleeve 22 is anchored. Within this sleeve is a square nut 23which is thus turned by turning of the knob I5. This nut contains athreaded post 2li which is rotatably journaled in the sole plate at itsbottom and which has a head 25 fastened within a plate 25 in the handle.

The square nut 23 is provided at its hase with a collar 27 having agroove 2&3. A broken rocker arm 2S is pivotally mounted in a bracket3.13. This rocker arm is enga-ged at its iront end hy the sides of thegroove 2t?. The other end of the rocker arm bears against a post 3l thatis fastened to the lower spring steel arm i9 which carries a Contactpoint l for the make and break switch. Thus the posi Si serves toposition the switch relative to the rst bimetal thermostat element I6.The broken rocker arm 23 is constructed so that `it acts as a rocker armin one direction only. This is provided for by having the `rocker arm intwo sections, each mounted on the same pivot, but with the front section'32 terminating around the rocker in a yoke, the ends of which hear uponthe top of 'the rear section 33 of the rocker arm. The positioning oithe rocker arm positions the switch relative to `the rst birnetalthermostat element iii which controls the temperature at which the ironoperates. This positioning is accompanied by rotation of the knob l5.When the knob I5 is rotated. the square nut "23 is movedup or down onthe post 24. This moves the collarvl'! and thus positions theroc'ker'arm 2S which operates as a rocker only when the collar 2 movesupwardly. When the collar is moved in ardownward direction, the rear ofthe rocker arm is kept .in proper position by means oi the spring steelsection` i9 pushing against the vrocker arm through post 3l. Such aconstruction is provided so that the rear portion 33 of 'the rocher armmay serve as a lever fnlcrumed at kone end around rocker arm pivot. Itfunctions as a lever when the free end of the vrear portion is pusheddown. The purpose .of this construction will be explained in greaterldetail hereinafter.

The setting of the thermostat is shown by the indicator 34, the end ofwhich points to the indicia mounted below the handle. The end of theindicator 34 appears through an arcuate opening 3E in the body of theiron. ln the particular form shown, this opening also passes through thehandle support i3, the indicator 34 is operated simultaneously with thesetting of the thermostat by means of a gear train 31 connected to thesquare nut 23. A ring gear 33 having a square central opening isslidably mounted on the square nut 23 and meshes with the largercircumference of a iiat ring reducing gear 39. The smaller circumferenceof the gear meshes with a toothed arcuate member attached to themounting 4I that bears the indicator 34. This mounting 4| is concentricwith the shaft 42 and is designed to turn independently of the shaft.

The temperature indicator preferably comprises a thermostatic coil 43secured to the sole plate Il of the iron in a central location. Thiscoil may be a conventional bimetal material in spiral shape adapted toexpand and contract as it heats and cools. At the inner end of the coilthere is located a post 42 that is rotatable under the influence of thebiinetal coil. The base of the post 42 is rotatably journaled in thesole plate. As a result when the temperature of the sole plate rises,the coil expands and turns the shaft. The temperature indicating means44 is secured to the neck of the shaft 42 and rotates therewith. Thismeans comprises a ring 45 having its cir-- cumferential portionunderlying the opening 36 and the point of the setting indicator 34. Thering may be painted appropriately, for example, with a red zone, ayellow zone, and a green zone, and is also marked so that whenever theyellow zone underlies the temperature setting the ternperature of theiron is the temperature indicated. On the other hand when the red zoneunderlies the setting indicator the temperature of the iron will beabove that required for a particular operM ating condition, and when thegreen zone underlies the pointer the temperature of the iron will bebelow that suitable for the preferred operating conditions. This methodof marking and the way in which the setting indicator and thethermometer may be calibrated is explained in detail in my copendingapplication referred to hereinabove.

On the rear section 33 of the broken rocker arm there is mounted anupwardly extending arm 49 projecting through an opening 5i] in thesupport plate for the reducing gear 39 (Figure '7). The upwardlyextending portion is located so that when the control knob I5 is turnedto a position corresponding to a high temperature the largercircumference of the ring reducing gear 39 contacts the inclined plate5D and pushes it down, thereby preventing locking of the parts. ThisservesJ to push the rear section 33 of the broken rocker arm down andbreak the contact of the control switch. It can be seen that when therear portion of the broken rocker arm is used in the above manner itacts as a lever fulcrumed at the point of pivot of the broken rockerarm.

After the new iron has been built and before it has been put inoperation it should be syne chronized so that the temperature indicatorwill coincide with the thermostat setting. This can conveniently be doneby means of a headless screw 5| positioned in the hub 52 of thetemperature indicating means 44. The screw presses against post 42 thatis attached to the bimetal thermostat 43 after the parts have beensynchronized.

The knob l5 which is used to control the operating temperature of theiron, has a finger contacting portion 46 extending beyond the main bodyportion of the knob. This extended portion is separated from the rest ofthe knob by deep circular grooves 41 on either side which serve to keepthe finger contacting portions 46 cool.

This application is a division of my copending application Serial No.591,911, led May 4, 1945.

The foregoing detailed description has been given for clearness ofunderstanding only, and no necessary limitations should be understoodtherefrom.

I claim:

1. In an electric iron having a handle and a body portion, a thermostatin the body adjacent the heating element, a switch operated by saidthermostat for turning electric current on and oi, and afinger-manipulative rotatable member on said handle for adjusting theswitch to any desired setting, a broken rocker arm operable as a rockerarm in one directionl only for positioning said switch, one end of saidrocker arm operating on said switch when the other end is adjusted bysaidrotatable member, setting-indicating means operated by saidrotatable member through a gear train, means operated by said rotatablemember also through said gear train for displacing the switch end ofsaid rocker arm to disengage the switch when said rotatable member isturned to a position corresponding to a very high temperature, thebroken rocker arm separating when moved in this direction so that theswitch end is a lever fulcrumed at one end.

2. The electric iron of claim 1 wherein said means for displacing theswitch end of said rocker arm comprises a portion of said gear train.

3. In an electric iron having a handle and a body portion, a thermostatin the body adjacent the heating element, a. switch operated by saidthermostat for turning electric current on and ofi", and afinger-manipulative rotatable member on said handle for adjusting theswitch to any desired setting relative to said thermostat for regulatingthe operating temperature in said iron, a broken rocker arm operable assuch in one direction only, one end of said rocker arm being positionedby movement of the said rotatable member to position said switchrelative to the thermostat, setting-indicating means also operated bysaid rotatable member through a gear train, and aninclined bearing plateon the end of the switch arm of the broken rocker and adapted to beengaged by a portion of the gear train to disconnect the switch whensaid rotatable member is turned to a position corresponding to a veryhigh temperature, the broken rocker separating when moved in thisdirection so that the switch end is a lever fulcrumed at the rocker axisof the rocker.

4. In an electric iron having a handle and a body portion and a heatingelement, a thermostat in the body portion adjacent the heating element,a switch operated by said thermostat for turning electric current on andoff and a ngermanipulative rotatable member for adjusting the switch toa desired setting, lever means for bearing directly against said switchand operated by said rotatable member for said adjusting of the switch,setting-indicating means also operated by said rotatable member andincluding a gear train, and rigid means operated by said rotatablemember through said gear train for displacing the switch end of saidlever means to disengage the switch when said rotatable member is turnedto a position at one end of its path of movement.

5. The electric iron of claim 1 wherein said rigid means includes anextending portion on the switch end of said lever means normallypositioned to be contacted by said gear train when said lever means isdisplaced to disengage the switch.

CHARLES H. SPARKLIN.

REFERENCES CITED The following references are of record in the i-lle ofthis patent:

Number 10 Number Great Britain Jan. 18, 1944 Certificate of CorrectionPatent No. 2,541,119 February 13, 1951 CHARLES H. SPARKLIN It is herebycertified that error appears in the printed specification of the abovenumbered patent requiring correction as follows:

Column 5, line 3, for the Claim reference numeral 1 read 4;

and that the said Letters Patent should be read as corrected above, sothat the same may conform to the record of the ease in the Patent Oiice.

Signed and sealed this 15th day of May, A. D. 1951 THOMAS F. MURPHY,

Assistant Commissioner of Patents.

Certificate of Correction Patent No. 2,541,119 February 13, 1951 CHARLESH. SPARKLIN It is hereby certified that error appears in the printedspecification of the above numbered patent requiring correction asfollows:

Column 5, line 3, for the claim reference numeral 1 read 4;

and that the said Letters Patent `should be read as corrected above, sothat the same may conform to the record of the case in the Patent Oce.

Signed and sealed this 15th day of May, A. D. 1951.

THOMAS F. MURPHY,

